PDA

View Full Version : Ford 9" rear-end questions



brgarris
02-01-2015, 05:07 PM
About to pull my 3rd member due to a pinion seal leak. Figured while I had it out I may put a different gear ratio in. Currently I have an LS3 525HP with 3.50 gear ratio. The transmission is a T56 magnum with the following ratios: 2.66 1.78 1.30 1.0 .80 .63.

Would anyone recommend a different rear gear ratio? I was thinking about going with a 3.70, but didnt know how much of a difference it would make. Send some recommendations if you have a similar setup!!!

Schwartz Performance
02-01-2015, 06:03 PM
The 3.70 won't change the rpm much, maybe 150rpm max.
Since the 525hp version has mostly top end horsepower, 3.70 wouldn't be a bad choice.. If you have taller than a 26" tire I'd recommend that. Otherwise just stick with the 3.50.

-Dale

brgarris
02-02-2015, 04:53 PM
Dale thanks for the prompt response. I am running 335/30-19 tires which would be ~26.9" tall. I am actually thinking about going with a 3.89 gear now....may help get some bottom end on the car. Thoughts?

Schwartz Performance
02-02-2015, 05:27 PM
Yeah with that combo and rear tire a 3.89 would be good too. I don't recommend lower than 3.70 with that rear tire .

-Dale

TheJDMan
02-03-2015, 06:36 PM
I'm running a SBC, 26" tire, T56 and 3.89 rear gear in a 9". It works well for highway driving and it is a blast around town.